Which statements about humidifier connections are true?

Which statements about humidifier connections are true?

• A. Bypass connects between supply side and return side
• B. Fan powered connects to the supply plenum
• C. Both of the above
• D. Neither of the above

Answer: (C)

Understanding how humidifiers join the duct system helps explain why both statements are correct. A bypass humidifier is connected between the supply and return ducts, letting a portion of the supply air flow through a wetted media and back into the return path without its own fan. A fan-powered humidifier includes a small built-in blower and is typically installed so it draws air from the return duct, passes it through the wetted media, and then discharges the humidified air into the supply plenum. Because these are the two common ways humidifiers are connected in HVAC systems, both descriptions describe real, standard configurations.

Understanding how humidifiers join the duct system helps explain why both statements are correct. A bypass humidifier is connected between the supply and return ducts, letting a portion of the supply air flow through a wetted media and back into the return path without its own fan. A fan-powered humidifier includes a small built-in blower and is typically installed so it draws air from the return duct, passes it through the wetted media, and then discharges the humidified air into the supply plenum. Because these are the two common ways humidifiers are connected in HVAC systems, both descriptions describe real, standard configurations.